Investigation of the Effect of Cerium Doping on the Electrical Properties and Leakage Current Behavior of Lead Zirconate Thin Films Derived by the Sol–Gel Method

Abstract

Undoped and cerium (Ce)‐doped (1 and 5 mol%) antiferroelectric thin films were obtained by a sol–gel process. All lead zirconate, PbZrO3 (denoted as PZ), films crystallized in the perovskite phase with a full [111] pseudocubic orientation and with a uniform microstructure. X‐ray photoelectron spectroscopic investigations revealed that the oxidation state of Ce is 3+ leading to an A‐site donor doping. Ce doping causes a decrease in the dielectric constant from 200 to 155 and an increase in the forward switching fields from 275 to 296 kV/cm. However, it also leads to a significant decrease in the leakage current density and this effect is more pronounced for the 5% doping case, where an order of magnitude lower leakage current is obtained compared with the undoped PZ. Analyses of leakage current behavior indicate dominance of a space charge limited current type leakage current and also a possible contribution from a Poole–Frenkel type emission in certain temperature or field regimes.

Enhancement of Energy Storage Density and Efficiency of PbHfO3 Doped with La Antiferroelectric Thin Films

“…This result is in good agreement with the properties of other types of perovskite materials . This result can be mainly attributed to the random distribution of La 3+ at the A-site of the perovskite structure, which may relatively increase the disorder of the cation at the A-site and alter the lattice structure …”

“…Figure also shows the energy dispersive spectrometry mapping of the PLH-0.01 film. The homogeneous diffusion of La 3+ into the lattice structure of the PbHfO 3 group increases the disorder of the cations at the A-sites and changes the lattice structure …”

“…This is mainly because La 3+ , which has a small ionic radius (1.36 Å), replaced Pb 2+ (1.49 Å) at the A-site, reducing t and improving E BDS as well as the stability of the antiferroelectric phase . In addition, the increase in the La 3+ content also causes a decrease in the P max of the sample (from 73.8 μC/cm 2 (PLH-0.00) to 45.8 μC/cm 2 (PLH-0.03)), which may be due to the A-site vacancies in the perovskite. , …”

“…The stabilities of W rec and η decreased as the La 3+ content increased to 0.03. This may be attributed to the high content of La 3+ , which results in creating vacancies in the A-site of the perovskite structure. , …”

Energy Storage Performance of PZT/PZ Composite Films Obtained by Sol–Gel Method

“…The positive linear relationship between the log ( J ) and log ( E ) was obtained, indicating that the films show the space charge limited current behaviors, so the space charge is the main reason for the leakage of the films rather than the oxygen vacancy. [ 34 ] In addition, it is worth mentioning that the slope increases in the films annealed at 620 °C for 6 min as the external electric field increases, which could be attributed to the charge accumulation at the film interface. [ 35 ] All the prepared films have low leakage current, which could enhance the breakdown field strength, improving the energy storage density.…”